The arrival of mobile Internet era makes intelligent mobile terminal equipment become gradually a communication and entertainment tool requisite to be carried by people in life, at work and on a journey. Moreover, with the rapid development of the On-The-Go (OTG) technology, data processing equipment between intelligent mobile terminals in an OTG mode also emerges as the times require. However, intelligent mobile terminals with which the current equipment can be connected are relatively simple and cannot simultaneously support data transmission between the intelligent mobile terminals and personal computers (PCs). In addition, since related portable devices only support universal serial bus (USB) or only support connection of card reader interfaces, to meet different demands, people usually have to carry a variety of data transmission and storage accessories in their luggage, this brings a lot of burden and inconvenience for people. Therefore, there is an urgent demand for developing a multifunctional portable device that can support multiple data transmission modes, can be connected with multiple intelligent mobile terminals, and can support both USB and card reader interfaces, thus reducing users' baggage burden and enhancing the users' experience.